Reverse gear



Nov. 26, 1940. T. FAWICK Re. 21,630

REVERSE GEAR Original Filed March 16, 1935 :s Sheets-Sheet 1 Nov. 26, 1940. T. L. FAwlcK Re. 21,630

REVERSE GEAR Original Filed March 16, 1935 3 Sheets-Sheet 5 Reiesued Nov. 1940 UNITED STATES PATENT OFFICE I Thomas i zfifh fxn, I Original No. 2,187,967, dated January 23, 1940,

Serial No. 11505, March 16, 1935.

Application for reissue flied April 22, 1940, Serial No.

Claims.

The present invention relates generally to transmissions and is particularly concerned with the provision of a new and improved reversing gear for marine use.

5 The principal object of the present invention is the provision of a reversing gear having means not only providing for driving both forward and rearward but, in addition, serving as means for connecting and disconnecting the power, thereby replacing the usual main power clutch.

A further object of the present invention is the provision of clutch means adapted to be frictionally engaged, permitting limited slippage, in starting up under load and maneuvering, with associated means arranged after the load is moving for connecting the driving and driven parts together in a positive manner to be driven at a one-to-one ratio without any slippage as is usually desirable when starting. A further object of the present invention is the provision in a clutch or transmission of this type of improved shifting mechanism operable to bring about, first, frictional engagement during starting and maneuvering and, second, positive one-to-one engagement without slipping, and a still further object of the present invention is to lock the shifting mechanism in such positive position after the starting and maneuvering have been completed.

More specifically, an additional object of the present invention is the provision of reversing gear for marine use and the like which embodies low angle conical driving clutch members, which are oppositely rotatable in connection with a 85 shiftable companion clutch member cooperating therewith during initial engagement to transmit torque for starting and maneuvering, the driving and driven parts being subsequently connected for positive engagement, either by additional pressure on the clutches or by associated jaw clutch mechanism or the like. In this connection, it is a further object of the present invention to provide improved bearing means for supporting the driving and driven shafts, in such'a manner that a short, compact and sturdy transmission is provided and in which the space required is a minimum. Still further, another object of the present invention is the provision of improved supporting means for a gear reduction associated with the transmission, the same principles being applicable to an overdrive if higher speed is required.

Another object of the present invention is the provision of a shiftable combination of friction and positively acting clutch means, with the (Cl. lb-377) friction clutches operable to transmit driving torque during starting and maneuvering and the positively acting clutch means serving to connect the driving and driven members together without slippage after the load is moving. In this connection, a.v further object of the present invention is the provision of new and improved synchronizing mechanism arranged to prevent the engagement of the positive drive unless or until the driving and driven parts are rotating together, and a 'still further object of the present invention is the provision of synchronizing mechanism making use of the friction clutches which, in the first instance, are adapted to transmit driving torque during starting and maneuvering, as aforesaid.

These and other objects and advantages of the present invention will be apparent to those skilled in the art after a consideration of the following detailed description of the preferred structural forms which are illustrated in the accompanying drawings forming a part of this specification.

In the drawings:

Figure 1 is a vertical longitudinal section taken through a transmission embodying the principles of the present invention;

Figure 2 is a similar sectional view showing a modified form of the present invention;

Figure 3 is a perspective view, with certain parts being shown in section, illustrating the arrangement of the synchronizing means employed in the transmission shown in Figure 2;

Figure 4 is a section taken along the line 4-4 of Figure 2;

Figure 5 is a fragmentary sectional view showing the positions of the parts after the positive clutch means has been engaged; and

Figure 6 is a. view showing the serrations formed on the conical clutch faces Referring now to the drawings, and more particularly to Figure l, the reference numeral I indicates the gear case or housing of the reversing gear or transmission, the gear case being provided with a forward wall 2 and a rear wall 3 having suitable openings therein to receive the supporting bearings and the shift rods and other parts. The forward portion of the case I may be formed, as at I, to receive the flywheel 4 of the engine or other source of power, if desired, .the flywheel 4 being secured to the crank shaft 5 of the motor. The driving shaft of the transmission is indicated in its entirety by the reference numeral 6 and includes the tubular member having a splined internal sectionlatitsforwardendbywhichthedrlvng shaft is directly connected to the motor. lsbyashortstubshaftsection I, withoutthe nterpositionofanenainechitchorthelike. [he drive shaft 6 of the transmission is iourialed by suitable bearing means I in the front valllofthegearcase Landthebearlngmeans Icomprisesaninnerracelsecurelyflxedtothe ;ubulard'riveshafttbetweenagear ll anda .hreaded nut II, the gear ll being secured, as :y a key It, to the forward end of the drive shaft. Theouterraceofthebearlngmeans I is indicated by the reference numeral II and scarriedbyaflangedcollar It securedtothe frontwalliofthe gearcasebycapscrews ll, whicharealsoutilisedinattachlngacap ltto ihegearcasatbecap llhavlnganinternal Elange ll cooperating with the member I for retaining the outer race II in place. A conventionaloilringilisemployedtosealthe iriveshaftinthe casingtopreventloss ofluoricant.

Therearendofthedrivingshaft iissupported by needle point bearings 25 on the driven shaft It adjacent its rear end. The driven shaft Itissupported atits forward end andisdisposed within, the tubular driving shaft by means of a bronze bushing 21 or other form of anti-friction means, such as a roller bearing, the anti-friction means 21 being disposed substantially in the planes of the gear Ill and the bearing means I. The rear end of the driven shaft 2 is carried by suitable anti-friction means 3. including an inner race II and an outer race II. The inner race is clamped against the rear ends of splines 34, the latter forming a splined section between the bearing means 25 and the bearing means 30. The inner race 3| is clamped against the ends of the splines 34 by a retainer ring 31 screwed onto a threaded portion 38 at the rear end of the driven shaft 28 and held by a lock washer 89 or the like. The driven shaft 26 terminates rearwardly in a pinion I which will be referred to later. The outer bearing race 32 is carried in a bearing retainer or support I! having its lower half provided with a flange 46 receiving attaching cap screws 41, the upper portion of the bearing retainer 4! fitting in a recess 50 formed at the upper portion of an auxiliary housing II enclosing the pinion Ill and associated parts and which will be referred to later. It will be noted, however, that the auxiliary housing II is held in place by cap screws 52 and bolts BI, being attached to the rear wall I of the gear me or housing I.

The rear end of the tubular driving shaft 6 carries a driving clutch member 60 disposed in the plane of the needle point bearings 25. The driving clutch member I carries a part 8| having a conical friction clutching surface, and journaled for rotation on the driving shaft 5, as by needle point bearings 04, is a reverse driving member 85 carrying on its outer portion a conical friction clutch member ii, the angularity of the latter being substantially equal but opposite to the angularity of the conical friction clutch member ll, as best shown in Figure 1. Both of the conical clutching portions ti and 66 are preferably bronze or the like. and each has a radially inwardly extending flange I to take care of all axially directed thrusts. The conical members ti and I are secured to the driving members ll and 5, respectively, by any suitable means, such as keys 6| carried by said membersanddisposedinslots i9 formedinthe driving members. The reverse driving member II also includes a pinion section II which is in constant mesh with a pinion ll secured, as by a key 12, onto the hub portion ll of a reverse gear II, the latter being driven from the gear II on the driving shaft I by a reverse idler (not shown) of conventional construction. From Figure 1 it will be observed that the gear ll is of the same diameter as the corresponding gear section of the reverse gear 14, and that the pinion III is of the same diameter as the pinion ll. Therefore, the reverse driving member 65 will be driven in a reverse direction at the same speed that the clutch member I is driven in a forward direction.

A bronze thrust washer I is disposed between the two driving members 60 and 65, and a similar thrust washer I8 is disposed between the forward end of the reverse driving member 65 and the rear end of the gear III on the driving shaft 5. As best shown in Figure 1, the forward portion of the gear III carries a flange ll against which the inner race 9, referred to above, is secured by the clamping nut II. The gear I. thus serves as a flxed abutment for not only the inner race 9 but also the thrust bearing It and the associated reverse driving member 65. The thrust bearing It prevents rearward axial displacement of the reverse driving member 65. The driving member ill, being carried directly on the driving shaft 5, has been referred to as the forward driving member while the member 65, driven through reverse gears, has been referred to as the reverse driving member, but it will be understood that these terms are merely relative.

The reverse gear 13 is supported for rotation by needle point hearings on a shaft 18 held against rotation by a flange I9 bolted to the front wall 2.

The driven clutch part, optionally engageable with either of the driving clutch parts 6i and 66, is indicated in its entirety by the reference numeral 80 and includes a double cone ring 8| having oppositely disposed conical clutch surfaces 82 and 83 engageable, respectively, with the conical clutch members GI and 66. The double cone ring Si is secured by cap screws 85 to the flange 86 of a shiftable member 81 movably mounted on the splined section 34 of the driven shaft. As is obvious, when the member 81 and the attached double cone clutch ring ll are shifted rearwardly to the right in Figure 1, the surface 82 frictionally engages the conical surface on the clutch member SI, and when the parts ill and 81 are shifted in the other direction the other friction clutch, including the conical surface 83 on the ring Ill and the driving clutch member 66, is engaged. Both of these cone clutches are of the low angle type and are capable of transmitting large forces when securely engaged. As best shown in Figure 6, the bronze driving clutch members GI and 66 are provided with serrated conical faces 88 and 89 for the purpose of providing for the rapid flow of oil toward and away from the contacting surface when the clutches are being engaged and dis- The shiftable driven member an is shifted from neutral (Figure l) to either forward or reverse driving position by means of a shift yoke ill clamped by bolt means ltl to a movable shift rod I02. The lower portion of the shift yoke Ill is provided with a shoulder I05, against which a bearing race I66 is held, as by a retainer ring I01, and the hub portion of the member 61 carries an inner race I60, retained in place by a nut member I00. Anti-friction balls III are disposed between the races I06 and Ill and operate in conjunction therewith to shift the member 06 axially along the splined section 34 of the driven shaft in response to movements of the shift rod I02.

Mountedintheupperportionof thegearcase I is a novel form of shifting means interconnected, as will be described below, with the shiftable driven member 66 in such a way that the initial movement of the member 06 in either direction under the control of the operator will engage one of the friction clutches so as to transmit torque to the driven shaft for purposes of starting the craft and maneuvering the same, the novel shifting mechanism also being then adapted to exert an increased force and to be locked in a position so as to firmly engage one or the other of the friction clutches, depending upon which way the member 60 is moved, so as to transmit the torque positively and directly from the driving to the driven parts without slippage. The mechanism for shifting the rod I02 from one position to another is housed within a cover plate IIB secured to the case I by cap screws H0 and includes a. toggle casting I having supporting stub shafts I2I and I22 secured thereto, as by taper pins I23, and shiftably mounted in recesses I24 formed in the front and rear walls 2 and 3 of the gear case and closed to prevent loss of lubricant by plates I25. The casting I20 includes laterally spaced side wall portions I30 having notches I3I formed therein to accommodate a transversely disposed shiftin and locking shaft I33 on the outer end of which a shift lever I34 or the like is secured. Between the side wall portions I30 the shaft I33 carries keyed thereto a doubleended member I36 having oppositely disposed arms I31 and I36 provided with recesses to receive the swivel studs I40 and I. Similar swivel studs I42 and I43 are supported in the side wall portions I30 of the casting I20, and compression'springs I46 and I41 are disposed between the respective pairs of swivel studs, each spring embracing a toggle rod I46 passing through an aperture in the upper swivel stud and threaded, as at I50, into the lower swivel stud. The shift rod I02 is provided with a central notch I53 in which an operating lug I54 carried by the casting member I20 is disposed, so that when the casting member is shifted in either direction the shift rod I02 is moved in that direction, carrying with it the shift fork I00 and the shiftable driven member 80.

The operation of the mechanism described above is substantially as follows. The shift lever I34 is rocked in one direction to engage forward drive and in the other direction to engage reverse drive. In the embodiment illustrated, when the lever I34 is swung counter-clockwise the shiftable clutch member 80 is moved to the left and forces the conical clutching surface 83 into driving engagement with the companion friction clutch member 66 carried on the reverse driving member 65. The shifting of the parts, due to the counter-clockwise movement of the lever I34, is brought about as follows. When the lever I34 is moved away from its neutral position, counter-clockwise as viewed in Figure 1, the spring I46 is'compressed to an extent, depending upon the amount the lever I34 has been moved and the toggle rod I46 extends or is swung downwardly. The compression on the spring I46 establishes a horizontal component tmding' to shift the casting member I20 to the left, and this, as will be obvious, moves the clutching conical surface 63 into driving engagement with the conical clutch member 66 with sumcient force that drivingtorque is transmitted from the driving shaft 5 through the member 65 and the member 66 to the driven shaft 26 for starting and maneuvering the craft. Limited slippage is provided for, to accommodate starting but the amount of slippage is dependent upon the extent of swinging of the gear shift lever I34, the more the latter is swung to the left the greater will be the compression of the spring I46 and the greater will be the force with which the conical cooperating parts are held together, and the harder they are forced together the less will be the slippage. After the craft is under way, the movement of the gear shift lever I34 to the left can be completed, and when this is done the swivel stud I40 is swung with its standard just below the line joining the centers of the shaft I33 and the swivel stud I42. This marks the maximum compression of the spring I46 and the parts are so arranged that this is suflicient to hold the members together so that they rotate as one without any slippage under maximum loads. To prevent the lever I34 from swinging too far in either direction, the lower portion of the double-ended lever I36 is provided with abutment projections I55 which cooperate,

respectively, with lugs I56 carried by the lower wall of the casting member I20. ment these lugs hold the parts tion.

The movement of the shiftable clutch member 06 in the opposite direction, that is, to the right as viewed in Figure 1, is brought about by a clockwise movement of the shift lever I34, which compresses the other spring I41. The initial compression of this member causes the clutching surfaces 6I and 62 to engage for transmitting the torque for starting and maneuvering, but when the lever I34 is swung until its stop lugs I45 and I50 are in engagement the spring I41 experiences its maximum compression and the clutch parts 6I and 62 are held together to rotate as one without any slippage, even under maximum loads. The serrated faces on the clutch members 6| and 66, the low angle of their conical faces and the relatively large diameters of these parts provide means capable of transmitting relatively great amounts of power, and the bearing supports 1 and 21 for the forward ends of the tubular shaft and the driven shaft 26, over which the tubular shaft 5 is disposed, and the,bearing means and for the rear ends of the shafts provide a sturdy support for the transmission parts capable of transmitting such amounts of power.

In some types of marine work it may be desirable to provide reduction gearing mechanism for the above described reverse gear, and to this end I propose to mount within the auxiliary housing 5| an internal gear member I60 having internal teeth I6I and a shaft section I62 supported by anti-friction bearing means I63 in the rear portion of the auxiliary housing 5|, and according to the principles of the present invention the internal gear member I60 is provided with exterior anti-friction bearing means I 65, being in the form of rollers disposed between flanges I66 and I61 formed on the outer pe- When in abutin locked relaripheralportionoftheinternalgearilland gear pini 4|.andtheteethon thelatterarehelicalsothattheunitwillbepracticallynoiseless. and the same is true of thegears effecting the drive of the member 05. The bearing ltlisarrangedtotaketheaxlalthrusts internal gear member I" is subbearing means I and II are artake the axial thrusts to which the and driven shafts are respectively sub- Thus, by virtue of this construction. a

sturdy transmission is proconventional oil seal I04 is arranged t loss of lubricant from the rear end the auxiliary housing ll.

some cases. as where excessive amounts power are required to be transmitted, some form of positive engagement means, cooperating with starting and maneuvering friction clutches. is a desirable provision. and in the form of I the present invention shown in Figure 2 I have shown a construction embodying friction clutches for starting and maneuvering the craft and associated positive or Jaw clutch means arranged to'be engaged when the driving and driven shafts I begin to rotate in synchronlsm or at a one-toone ratio.

Referring now more particularly to Figure 2, in which it will be observed that many of the parts are of substantially the same form and a construction as described above in connection with Figure 1, and hence the same reference numeralshavebeenappliedtosimilarparts. In the construction shown in Figure 2. the driving shaft and the driven shafts are of practically the same construction as described above, except that where the driven shaft 28 in Figure 1 carries a relatively long splined section 24. the drivenshaft2ishowninFigure2isprovided with a radially extending flange provided with a teeth serving as splines, although they are shorterthanthesplinesshowninFigureLaswill be described latter.

Thetnlmlardriveshaft tissupportedinpractically the same manner as described above and,

uintheplane oftheneedle pointbearings "is provided with a driving clutch member 2 to g which is secured, as by rivets 2'2, a friction clutch member 2|! having a conical outer clutching surface 204. The rear end of the drive shaft lisprovidedwithaflangeIl'Ihavingexterior teeth2llservingasthedrivingpartofapositive or law clutch. The reverse member '5 in theconstructionshowninl 'lgure2isalsoprovided with a positive clutch member in the form laofaflangelilcarrledbyorforminganintegralpart of-the reverse driving member GI andprovidedwithexternal teeth 2. Thedrivingreversememberiialsocarriesafricflon a s g 8 F 2? i? clutch member 2l2 luring an exterior conical I clutching surface 2" and securedtothe member-OI byrivets 2|! orthelike. Preferably. the friction clutch members 2|! and M2 are formed ofthesamematerialasdescribed aboveandmay, ifdmired.havethesm'faces2l4and2llserrated flinthemannershowninFlgurec.

The driven shaft 2 in the form of the construction shown in Figure 2 is, like that shown in Figure 1, provided with a splined section dis'- posed between the needle pointbearings 2| which carry the rear end of the driving shaft-l and g the bearings it which support the rear end of thedrivenshaft2l,butinl"igure2thesplined portion takes the form of a radially outwardly extending flange 22. having a series of external teeth 22l which for all practical purposes serve 10 the same purpose as the spline teeth 84 described above, namely. to maintain a constant but slidable connection between the driven clutch parts and the driven shaft.

The shiftable member which serves to connect is either of the driving clutches with the driven shaft takes the form of a two-part member indicated in its entirety by the reference numeral 224. The part Ill of the shiftable clutch member 23. includes a double cone member 222 havan ing surfaces 232 and 234 engageable, respectively, with the clutch members 202 and 2i2, and secured, as by rivets 226, to the double cone member 232 is a synchronizing ring 221 which forms a rigid part of the member 22! and is provided 95 with a plurality of recesses 24. which will be referred to later. The other part of the shiftable clutch member 23. is indicated by the reference numeral 242 and includes a sleeve and cylindrical member having a pair of radially outa war-W extending flanges 242 and 244 between which the arms 24! of shift yoke 246 are adapted to be disposed. The member 242 carries a plurality of studs. of hexagonal formation, as indicated in Figure 3, and securely held in place therein in any suitable manner, as by rin s 25.. The studs 24! have radially inner ends dispoud within the recesses 24. of the synchronizing ring 221. The forward portion of the shiftable clutch part 242 carries a plurality of clutch teeth 252 adapted to engage the clutch teeth 2 formed on the reverse drive member I in this form of the invention, and the rear portion of the shiftable clutch part 242 carries a plurality of teeth 2" which are engageable with the teeth 248 formed on the spline flange-2.1. The rearmost end of the member 242 carries a plurality of internal teeth 25! which are of sufhcient length to remain in driving engagement with the teeth 22l formed on the spline flange 22. so that the clutch part 242 rotates at all times with the driven shaft 26. whether in neutral or reverse or forward position. Suitable anti-friction hearing means (not shown) may be disposed between the shift yoke 24' and the flanges 242 and 244.

The two parts 23l and 242 of the shiftable member-2i! are movable with respect to each other, but spring pressed detent means is provided for causing the two parts to move together. Such detent means is indicated in its entirety 00 by the reference numeral 21. and is disposed in one of the driving studs 24!. Each of the detent means 214 includes a spring 2' in a recess 212 in the associated stud 242 and presslngagainstasteelball2l8whichisdisp0sedina short groove 214 formed in the outer surface of the double cone clutch member 222. As best shown in Figure 3, the groove 214 is elongated so that the two parts 23l and 242 of the clutch member 224 may rotate relative -to one another through a small angle without resistance but, up to the limit of offered by the spring pressed ball 2'", when the outer clutch member 242 is shifted the inner clutch member 2" moves with it. fl

The synchronising rinl 231 ha the specially ionnedopenings lll-antLasbestshowninPlgures3and4,theseopeningsareofapproximateiy cnmiiorm proportions and are provided with generally semi-hexagonal intermediate recemes 211 and 213 and laterally disposed recesses Ill .andlll ofsimilarformbut somewhatdeeper. Theassociatedstud 24lisadaptedtobedisposed inanyoneoftheserecemesintheoperationof 1o thetransmisslon, as will be Theshiftyoke 24lismountedinanysuitable means upon the slidable shift rod 2ll, preferably being securely clamped thereto by a clamping bolt 233, and the rod 2 is slidably disposed is in suitably formed openings 231 and 2 in the front andrearwalls2andl ofthetransmission case. '1herearopening2llismadetl8ht a plate 233 in the outer end thereof, and the forward opening 2" is provided with a bushing 2ll 20 through which the forward end of the shift rod 233 extends to a point outside the gear case. This end of the rod 2l5 is provided with a notch 294 which receives thetlower end 235 of the gear shift lever 2 which has a ball 2" formed thereas in and adapted to be rockably disposed in a socket 293 formed in the forward end 3" of the gear case cover III. A plate 302 is secured to the end 3ll, as by bolts 3l3, for the purpose of holding the gear shift lever 23 in place. Also, 30 the forward end of the cover 3ll is provided with a bore lll which receives a spring 3ll that is held in place by the retaining plate "2 and presses downwardly against a detent 3l1. The shift rod 235 is provided with three recesses or as grooves 3", 3 and 3", and a hole in the bushing 2ll permits the ball 3" to engage in any of these grooves for the purpose of easily retaining the shift rod 235 in either a neutral, forward or reverse position, the groove 30! defining o the forward position, that is, when the craft is driven forwardly, and the groove 3" defines the reverse position.

The operation of the modification shown in Figure 2, having particular reference to the syn- 4g chronizing mechanism by which the positive clutch means are not engaged until the friction clutch means has started the craft and brought the same up to the speed desired, is as follows. Assuming that it is desired to move forward, the so gear shift lever 236 is swung forwardly in a counter-clockwise direction as viewed in Figure 2.- This wfll exert a rearward thrust of the shift rod 235, forcing the ball 3" upwardly against the tension of the spring 3ll. The initial move- 5| ment of the gear shift lever 286 and the shift rod 233 in the direction indicated first shifts the clutch part 242 rearwardly a slight amount, carrying with it, due to the action of the spring pressed ball 213 and its bearing against the sides so of the groove 214, the double cone clutch part 23l This causes the conical portion 233 thereof to engage the surface 204 on the driving conical clutch member 233, and as soon as this engagement is effected the rotation of the driving mem- 65 ber 2, shown by the arrow in Figure 3, drags with it the clutch part m until the lug 249, carried by the part 242, is engaged by the recess 211 in the synchronizing ring 231. Since the synchronizing ring 231 is riveted to the double 70 cone member 232 it forms an integral part thereof, and hence the continued rotation of the driving member2ll thus rotates not only the clutch part 23l but also the clutch part 242, and since the latter is continually in engagement with the '!l splined portion 22l oi the driven shaft 25 the latter-is thus driven by-the frictional en a ement of the clutching surfaces 2 and 233. These clutching surfaces are conical and have a relatively low angle of inclination so that by applying only moderate pressure against the 5 shaft lever 233 these surfaces can'be forced together withsuflicient pressure to start the craft and maneuver the same in getting the craft under way; As is obvious, the greater the force applied to pres the clutching surfaces 2 and 233 together the greater will be the amount of torque or force that can be transmitted by this friction means. This force is limited, however, by the resistance offered byrthe spring 21L However, when engagement is actually effected the rotation of the gear part 23I carries the notch 211, under the directions of shift assumed above into embracing engagement with the lug 243. As soon as this is accomplished any further shifting movement of the part 242 acts through the engagement of the lug 249 in the recess 211 and the transmission of starting and maneuvering torque therethrough to carry laterally with it the inner shiftable clutch part 23L Thus, more force can be exerted on the gear shift lever to 5 press the clutching surfaces together than would be possible if merely the spring pressed ball were relied upon to press the clutching parts together. The engagement of the recess 211 around the lug or stud 243 has a further purpose, namely, it serves under these conditions to absolutely prevent any movement of the member 242 suiiicient to carry the teeth 253 into engagement with the clutch member 201. This causes all the torsion exerted by the source of power transmitted to the driven shaft to be transmitted thereto through only the friction clutch means. That is, as long as the lug 249 is in the recess 211 it cannot be shifted into the lateral recess 280, but when the craft gets under way and starting and any necessary maneuvering has been effected, it is then desirable to bring the positive clutches in operation in order to prevent any possible slippage by the transmission of all of the power throughthe gripping friction surfaces. In the construction illustrated, all that is necessary to do to make it possible to engage the positive clutch means is to bring the driving and driven parts into synchronism so that the momentum of the craft will be enabled to rotate the member 242 relative to the drawing part 23 just sufficient to bring the lug 249 out of the recess 211 and into the central portion of the opening 240, and as soon as this occurs then additional pressure on the gear shift lever will move the clutch part 242 rearwardly, bringing the lug 249 into engagement with the recess 280 and, at the same time, bringing the positive clutch teeth 256 into engagement with teeth 208 on the driving member 2". Pressure on the gear shift lever, acting through the hexagonal lug 249 and angular edges of the recess 211 also makes it possible to shift the part 242 out of position shown in Figure 3 to the position shown in Figure 5. It is to be noted that the friction clutches are held in engagement by the pressure of the ball 213 against the walls of the groove 214 until after the toothed or positive clutches start to engage. Since the member 242 is always in engagement with the splined flanges 220, the final shifting movement of the clutch member 242 thus positively secures the driving and driven shafts in direct engagement (Figure 5) so that the torque is no longer transmitted through the friction clutches or the friction clutch elements. The ring member 231 and associated parts, including the lugs 24! on the member 242, thus serve as synchronizing means acting to prevent any engagement of the positive clutch parts until the driven shaft has been brought up to the speed desired and rotates in synchronism with the driving shaft 6 so as to make it possible to complete the shifting movement of the movable clutch part 242 to bring the lug 2 into the lateral recess Ill.

The operation ofthe mechanism in selecting reverse drive is substantially the same, the gear shift lever 29' being swung in a clockwise direction, as viewed in Figure 2, to move the shiftable parts forwardly of the gear case. rather than rearwardly as described above. Otherwise, the operation is substantially the same, the synchronizing mechanism serving to prevent any engagement between the positive clutch parts Ill and ill until the friction clutches serve their: purpose in getting the craft under way so that as soon as the parts rotate at substantially the same speed, the member 242 can be shifted to its positively engaged position in the gear case to bring the teeth 253 into mesh with the teeth 2 on the reverse driving member 65. The friction clutch elements are, however, positively held in engagement by the ball I" engaging one side of the groove 2'" until the teeth 2" and 253 are engaged, but after their engagement is complete the ball 21! is forced out of the groove 2' and no longer exerts any force against the friction clutch part I, the entire driving torque being taken by the positive toothed clutch parts.

As will be apparent from Figure 3, in selecting and effecting reverse drive, it is the intermediate recess 2" that engages the driving stud 249. and it is the recess 219 which finally receives the stud after synchronism has been effected.

While I have shown and described above the preferred forms of my invention, it will be apparent to those skilled in the art that the present invention is not to be limited to the particular details shown and described above, but that, in fact, widely different means may be employed in the practice of the broader aspects of my invention.

What I claim, therefore, and desire to secure by Letters Patent is:

1. A trion comprising a gear case, a tubular driving shaft mounted for rotation in said gear case, bearing means for the forward end of said tubular driving shaft, a driven shaft also mounted for rotation in said gear case, bearing means supporting the rear end of said driven shaft therein, the forward end of said driven shaft being disposed within and adjacent the forward end of said tubular driving shaft, hearing means supporting the forward end of said driven shaft in said tubular drive shaft, said bearing means being disposed adjacent the bearing means for the forward end of the latter,

bearing means adjacent the rear end of said driven shaft for supporting the rear end of said tubular drive shaft thereon, the portion of said driven shaft between said last named bearing means and the bearing means for the rear end of the driven shaft being splined, a driving member carried by said driving shaft, a second driving member mounted for rotation on said tubular drive shaft and driven therefrom differently than 'said first driving member, a shiftable member operatively connected with said splined section and movable from one position to another frictionallytoenii seeitheroi!saiddrivingmembers,

auxiliary housing secured to said gear case and enclosing said pinion, a final driven shaft mounted for rotation in said auxiliary housing, an internal gear member connected with said final driven shaft and meshing with said pinion, and anti-friction means disposed between the outer peripheral portion of said internal gear member and said auxiliary housing.

3. In a transmission, agear case, a driven shaft mounted for rotation therein and including a driven pinion extending rearwardly from the gear case, bearing means carried in the rear wall of said case for supporting said driven shaft, and auxiliary housing secured to said gear case and enclosing said pinion, a final driven shaft mounted for rotation in said auxiliary housing, an internal gear member connected with said final driven shaft and meshing with said pinion, anti-friction means disposed between the outer peripheral portion of said internal gear member and said auxiliary housing, said last named bearing means being capable of taking radially directed loads only, and anti-friction bearing means arranged to take both axial and radial loads for supporting said final driven shaft in said auxiliary housing.

4. In a reverse gear, a gear case, driving and driven shafts journaled for rotation therein, bearing means for the front end of said driving shaft, reversing gearing mounted adjacent said front bearing and including a part journaled for rotation on said driving shaft, means shiftable on said driven shaft and adapted to connect with either said driving shaft or said reversing gearing, a pinion carried at the rear end of the driven shaft, a final driven member including an internal gear meshing with said pinion, flanges formed on the peripheral portion of said internal gear member, and a plurality of anti-friction rollers disposed between said flanges and carried by said gear case to support said internal gear for rotation.

member and said direct driving member, a pinion on said intermediate driven shaft, a driven shaft, an internal gear on said driven shaft meshing with the pinion on said intermediate driven shaft, and a bearing for said internal gear and disposed outside said gear and in radial alignment with ai,cso

the toothed engagement between said gear and the pinion on the intermediate driven shaft.

6. In a reverse gear. the combination of a source of power, a driving shaft directly con- 6 nected therewith, a lay shaft geared to said driving shaft. a tubular reverse driving member geared to said lay shrft, said driving shaft extendin coaxially through said tubular reverse driving member, a direct driving member fixed on the 10 extending end of said-driving shaft in proximity to laid tubular reverse driving member, a driven shaft. a extending part on said driven teeth on the periphery of said part, clutch teeth on said tubular reverse driving member. clutch: teeth on me direct driving member,

a clutching member having clutch teeth in permanent engagement with the clutch teeth on the radially extending part on said driven shaft and clutch teeth shiftable into en agement selectively with the clutch teeth on the respective driving members. and means inclusive of friction clutch means serving to connect the driving and driven shafts for limited slippage to transmit torque therebetween.

7. In a reverse gear, the combination of a source of power, a driving shaft directly connected therewith, a lay shaft geared to said driving shaft, a tubular reverse driving member geared to said lay shaft, said driving shaft extending coaxially through said tubular reverse driving member, a direct driving member fixed on the extending end of said driving shaft in proximity to said tubular reverse driving member, an intermediate driven shaft, a radially extending part on said intermediate driven shaft, clutch teeth on the periphery of said part, clutch teeth on said tubular'reverse driving member, clutch teeth on said direct driving member, a clutching member having clutch teeth in permanent en- 40 gagement with the clutch teeth on the radially extending part on said intermediate driven shaft and clutch teeth shiftable into engagement selectively with the clutch teeth on the respective driving members, means inclusive of friction clutch means serving to connect the driving and driven shafts for limited slippage to transmit torque therebetween for starting and maneuvering, a pinion on said intermediate driven shaft, a driven shaft, and an internal gear on the last said driven shaft meshing with the pinion on said intermediate driven shaft.

8. A reverse gear comprising a casing, a driving shaft journaled for rotation therein and adapted to be connected to a source of power, a tubular reverse driving member mounted for rotation on said driving shaft adjacent one end thereof, gearing driven from said driving shaft for driving said reverse driving member at substantially the same speed as but in the opposite direction from said driving shaft, a pair of friction clutch elements, one fixed to said one end of the driving shaft and the other fixed to the adjacent end of said tubular reverse driving member, a driven shaft supported for rotation in said casing and held against axial movement therein, a companion friction clutch element carried in driving relation with said driven shaft and movable axially relative thereto, said pair of friction clutch elements having low angle friction surfaces and the companion clutch element embracing said pair of clutch elements and having two friction clutch surfaces on the inside disposed at a low angle corresponding to the angle of said pair of friction clutch elements, the angle of said friction elements being sufliciently low that adequate power is transmitted for starting and driving the craft through said friction elements optionally in either direction, and means for shifting said companion friction clutch element relative to said driven shaft and said pair of clutch elements to start and drive the craft in the selected direction.

9. In a reverse gear, the combination of a source of power, a tubular driving shaft connected therewith, a lay shaft geared to said driving shaft, a tubular reverse driving member geared to said lay shaft and driven thereby in the opposite direction from but at the same speed as said driving shaft, said driving shaft extending coaxially through said tubular reverse driving member, a'direct driving member fixed on the extending end of said driving shaft in proximity to said tubular reverse driving member, a driven shaft extending coaxially through said tubular driving shaft and supported at its inner end by the forward portion of the driving shaft, the rear end of said driven shaft supporting the rear end of said tubular driving shaft, an axially shiftable driven member splined to said driven shaft and optionally engageable frictionally with said tubular reverse driving member and said direct driving member for driving the craft in either direction, and thrust bearing means between said tubular reverse driving member and said tubular driving shaft for preventing relative axial movement therebetween in either direction.

10. A reverse gear comprising a tubular driving shaft, a casing supporting said driving shaft and having bearing means receiving said driving shaft and preventing axial movement thereof relative to the casing, a tubular reverse driving member mounted for rotation on said driving shaft, means driven from said driving shaft for driving said tubular reverse driving member in the opposite direction, said driving shaft extending coaxially through said tubular reverse driving member, a direct driving member fixed on the extending end of said driving shaft in proximity to the tubular reverse driving member, a driven shaft extending coaxially through the tubular driving shaft, hearing means supporting the inner end thereof in said tubular driving shaft adjacent said first bearing means, bearing means supporting the outer end of said driven shaft in said casing, said last named bearing means preventing axial movement of the driven shaft relative thereto, a driven member splined to said driven shaft, low angle cone clutch means on said driven member, said direct driving member and the tubular reverse driving member, whereby movement of said driven member into engagement with one or the other of said driving members serves to drive the craft in either direction, thrust bearings at opposite ends of said tubular reverse driving member and acting against said tubular driving shaft for preventing axial displacement of the reverse driving member relative to said driving shaft, and means for shifting said splined driven member, axial thrust due to the engagement of said low angle clutch means being taken by said first mentioned bearing means and axial thrust due to the movement of the splined member relative to the driven shaft being taken by the bearing means supporting the outer end of the latter.

11. The combination of a source of power and reverse gear comprising a driving shaft connected with said source of power, a driven shaft, means providing forward and reverse gearing including friction clutch means for starting in either forward or reverse, and positive clutch means arranged to connect said driving and driven shafts after driving has begun in the selected direction, said reverse gearing comprising two telescoped transmission shafts, two clutch structures mounted upon the telescoped shafts respectively and each including friction clutch means and positive clutch means, a mating clutch structure including mating members for the two friction clutch means and for the two positive clutch mans, an actuating member, and means so connecting the said actuating member to said mating members that it is common to all of them.

12. A reverse-gear transmission comprising a driving shaft, a driven shaft, and forward and reverse driving means interposed operatively between the two, said means comprising coaxial forward and reverse shafts one within the other, gearing connecting the forward and reverse shafts and compelling them to rotate in opposite directions, juxtaposed friction clutch members on the said coaxial shafts respectively and a positive clutch member on at least one of them, and mating clutch members on one of the two first-mentioned shafts and adapted to be engaged selectively with the said friction clutch membersand the said positive clutch member.

13. A reverse-gear transmission for driving a marine propeller, said transmission comprising a driving shaft, a marine propeller shaft, and forward and reverse driving means interposed operatively betweenthe two, said means comprising coaxial forward and reverse drive members one within the other, gearing connecting the said members and compelling them to rotate in opposite directions, juxtaposed, friction clutch members on said coaxial members respectively and a positive clutch member on at least one of them,

member.

and mating clutch members having drive relationiooneofthesaidshaftsandadaptedtobe engaged selectively with the said friction clutch members and the said positive clutch member.

14. A reverse-gear trn comprising a driving shaft, a driven shaft. and forward and reverse driving means interposed operatively between the two, said means comprising coaxial forward and reverse shafts one within the other. gearing connecting the forward and reverse shafts compelling them to rotate in opposite directi ns, juxtaposed friction clutch members on the said coaxial shafts respectively and oppositely tapered and a positive clutch member on at. least one of them, and mating clutch members on one of the two first-mentioned shafts and adapted to be engaged selectively with the said friction clutch members and the said positive clutch 15. a reverse-gear transmission comprising a. driving shaft,-a driven shaft, and forward and reverse driving means interposed operativeiy between the two, said means comprising coaxial forward and reverse shafts one within the other, gearing connecting the forward and reverse shafts and compelling them to rotate in opposite directions, juxtaposed friction clutch members on the said coaxial shafts respectively and ,a positive clutch member on at least one of them, and mating clutch members on one of the two first-mentioned shafts and adapted to be engaged selectively with the said friction clutch members and the said positive clutch member, an actuating member, and mechanical means so connecting said actuating member to said mating members that it is common to all of them.

moms L. FAWICK. 

